Portable water purifier with ultraviolet light source

ABSTRACT

A portable container is disclosed, providing a means for the purification of a fluid by ultraviolet radiation. The container houses the liquid and mates with the ultraviolet light source, which is powered by a battery attached thereto. Additionally, an ultraviolet light sensor is provided to shut off the ultraviolet light and notify the user when the water has received an adequate dose of ultraviolet radiation.

[0001] The present invention relates generally to a water purificationapparatus and, more particularly, to a portable water purifying andgermicidal disinfecting system that utilizes ultraviolet radiation toprepare water for human consumption.

BACKGROUND OF THE INVENTION

[0002] Natural water supplies can be contaminated by any number ofdisease-carrying microorganisms from bacteria to protozoa to viruses.Consuming water that contains these organisms can lead to cramps,vomiting, diarrhea and even more serious medical problems. For water tobe safe to drink, these microorganisms must be either rendered inactiveor removed.

[0003] There exists a need for portable water treatment systems forproviding water suitable for human consumption at remote locations. Thisneed exists, for example, in rural areas where sophisticated watertreatment facilities are not present, and in the aftermath of disasterssuch as earthquakes and hurricanes where the local water supply has beencontaminated or disrupted. While enjoying recreational activities ofextended periods of time, such as hiking or camping, there is a need forwater to be purified in relatively small quantities. In these instances,some effective method of treating local water supplies becomesnecessary.

[0004] Various devices have been developed to disinfect water usingirradiation of infected water with certain frequencies ofelectromagnetic radiation such as those in the ultra-violet range. U.S.Pat. No. 4,849,100 issued to Papandrea discloses a portable waterpurifier which shuts off the water flow therethrough upon sensing thatthe ultraviolet light intensity has fallen below a predetermined level,in an attempt to ensure that all of the water is sufficiently purified.U.S. Pat. No. 4,755,292 issued to Merriam discloses a portableultraviolet water sterilizer with ultraviolet reflective sidewalls, inan attempt to shield the user from harmful ultraviolet radiation andcause the water to be efficiently exposed to ultraviolet light.

[0005] The devices used heretofore have generally proved to beunsatisfactory for one or more reasons. Most irradiation waterpurification devices have been designed to remain stationary, having thewater flow through as it is exposed to ultraviolet light, and thusrequire the use of a pump. Certain apparatuses of this type becomecoated with materials opaque to ultraviolet light after repeated use,and thus prevents satisfactory disinfection. Other devices do notprovide a sufficient duration or intensity of ultraviolet light to fullydisinfect the water. Many of the portable devices fail to provide asufficient amount of ultraviolet light, as to do so might cause theultraviolet bulb to overheat and become inoperable. Other devices haverelied on the tendency of ultraviolet light to catalyze the formation ofozone from oxygen. However, these devices require a great deal of powerto be consumed, and if portable, a bulky power source to be attached.

[0006] A portable water system must be compact, lightweight, andconvenient to use. In addition to these requirements, a portable waterpurification system must be effective in purifying water to a suitablequality. It is also desirable that such a system not require theaddition of chemicals and the like to be added to the water which eithermay lessen the quality of the treated water or require additionalsupplies.

[0007] High levels and prolonged exposure to ultraviolet light has beenshown in recent years to cause various skin cancers, defects relating tohuman eyes, and the breakdown of human deoxyribonucleic acid. Therefore,it is desirable for the ultraviolet radiation utilized by the device tobe prevented from escaping the device and effecting those who wish tobenefit from the device's water purification.

[0008] A number of portable ultraviolet water purification devices haveattempted to fulfill this need. U.S. Pat. No. 4,849,100 issued toPapandrea discloses a portable water purifier which shuts off the waterflow therethrough upon sensing that the ultraviolet light intensity hasfallen below a predetermined level, in an attempt to ensure that all ofthe water is sufficiently purified. U.S. Pat. No. 4,755,292 issued toMerriam discloses a portable ultraviolet water sterilizer withultraviolet reflective sidewalls, in an attempt to shield the user fromharmful ultraviolet radiation and cause the water to be efficientlyexposed to ultraviolet light. However, these devices fall short ofproviding an efficient, durable, convenient, reliable portablepurification device for drinking water. For example, the Merriam deviceis not shaped to be carried but is more of a bucket, the light sourcedoes not secure or seal to the container, the container does not seal,and there is no provision for cooling the light source. The Papandreadevice requires water to flow therethrough making it poorly suited toportable use.

SUMMARY OF THE INVENTION

[0009] These problems of past devices have been overcome by the presentinvention, a portable water purification system. The portable waterpurification system of the present invention includes a container inwhich water is to be placed. Attached to the container is an ultravioletlight source which irradiates the water, the inside surfaces of the topand side portions of the container are coated with an ultravioletreflective material. The entire container is made of a material opaqueto ultraviolet light. A battery is provided in order to provide power tothe ultraviolet light source. Additionally, a sensor is provided inorder to determine when the water being purified has received anadequate dose of ultraviolet radiation. Upon this determination theoperator of the purification device is notified and the ultravioletlight source of the present invention is automatically shut off.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A better understanding of the present invention will be had uponreference to the following detailed description when read in conjunctionwith the accompanying drawings, wherein like reference characters referto like parts throughout the several views, and in which:

[0011]FIG. 1 is an elevated view of a first preferred embodiment of thepresent invention;

[0012]FIG. 2 is an elevated view of a second preferred embodiment of thepresent invention; and

[0013]FIG. 3 is an elevated exploded view of an alternative embodimentof the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

[0014] First referring to FIG. 1, a portable liquid purification systemaccording to the present invention is there shown. The portable liquidpurification system 10 includes a container surface 12, which generallydefines the boundaries of a liquid container 11. Water, or anotherliquid intended for human consumption may be poured into the container11. A lid 14 is then placed on the container 11 so as to seal thepurification system 10 from being in liquid communication with itssurroundings.

[0015] An ultraviolet light source 18 is removably secured to the bottomof the container surface 12 in order to provide the liquid inside thecontainer 11 with ultraviolet radiation. The ultraviolet radiation isprovided by an ultraviolet bulb (not shown in FIG. 1) of a type wellknown to those skilled in the art, an integral component of theultraviolet light source 18. The ultraviolet bulb may be a deuteriumlamp, or a high-pressure gas-filled arc lamp containing argon, xenon, ormercury, as is known in the art. The ultraviolet bulb may be powered bya battery, AC adapter, or solar cell (also not shown in FIG. 1).

[0016] The ultraviolet bulb is contained in the ultraviolet light source18 by a lens 22 and a source wall 20. The lens 22 is generallytransparent with respect to ultraviolet light, and may be formed fromquartz, fused silica, or a high tensile plastic resistant todiscoloration and degradation. Preferably the container 11 does not havea bottom wall, but instead the source 18 seals off the bottom of thecontainer when it is inserted into the recess 24. This provides thebenefit of allowing heat from the source 18 to conduct directly to theliquid in the container, thereby cooling the source. The lack of abottom wall also allows a user to thoroughly clean the inside of thecontainer 11 when the source is removed, thereby removing buildup fromthe inner surface. As is clear to those of skill in the art, there aremany ways in which the source 18 may be sealed to the bottom of thecontainer 11. For example, it may snap into place and seal off thebottom. When the source 18 is removed, a cover may be provided forsealing the bottom of the container 11 so that water may be sterilizedand stored without tying up the source. In this way, the source 18, maybe used with multiple containers. Alternatively, the container may havea transparent-to-ultraviolet bottom wall so that the container 11 willbold a liquid when the source 18 is removed without the need for acover. Either way, because ultraviolet radiation passes from the source,through the lens 22, and into the container 11, the ultravioletradiation generated by the ultraviolet bulb is allowed to effect theliquid in the container 11.

[0017] The container surface 12, as well as the source wall 20, aresubstantially opaque to ultraviolet radiation. Additionally, the devicewill preferably shutoff, or not turn on, if the lid 14, also made of amaterial substantially opaque with respect to ultraviolet light, is notsecured to the container surface 12. These characteristics protect theuser from hamiful ultraviolet radiation, which has been shown, insubstantial doses, to deteriorate human health.

[0018] In order to increase efficiency, a reflective coating 16 isprovided along the inner surface of container surface 12. The reflectivecoating 16 is substantially reflective with respect to ultraviolet lightso as to cause the liquid in the container to absorb a maximum amount ofthe ultraviolet radiation emitted by the ultraviolet bulb.

[0019] With reference now to FIG. 2, a second purification system 10according to the present invention is there shown. This embodiment issimilar to that illustrated in FIG. 1. However, this embodimentadditionally includes an ultraviolet sensor 26. The ultraviolet sensor26 determines when a sufficient amount of ultraviolet radiation has beenemitted to the liquid for the liquid to be safe for consumption. Uponmaking such a determination, the ultraviolet sensor 26 preferably causesthe ultraviolet bulb to stop emitting ultraviolet light. Additionally,or alternatively, the user is notified in some manner that thepurification of the liquid has been completed. This ultraviolet sensor26 may be a photovoltaic cell, phototube, photomultiplier tube, orsilicon diode, as is well known in the art. Obviously, the sensor 26 maybe used with other embodiments of the present invention. As is known tothose of skill in the art, the output of an ultraviolet light source 18may degrade over time due to aging. Also, the amount of ultravioletreaching the liquid may drop if the transparency of the lens 22 drops orsedimentation occurs. The sensor 26 allows a user to compensate for thiseffect and to make sure the liquid is ready to drink. As the lightsource 18 ages, the sensor will take longer to trigger, therebyincreasing the useful life of the source 18. It also avoids over use ofthe light source 18, preventing premature battery discharge.

[0020]FIG. 2 also shows that the ultraviolet light source 18, as well asthe bottom portion of the container surface 12 may be threaded so as toallow the ultraviolet light source 18 to be screwed into abutment withthe container surface 12. Obviously, the ultraviolet light source 18 mayalso be removed in an opposite manner. This screw together arrangementis an alternative to the snap together arrangement of FIG. 1. The screwtogether arrangement works well for containers with circular crosssections, as shown, but would be unsuitable for a container with anelliptical cross section. Another preferred embodiment of the presentinvention has an elliptical cross section to make the container easierto wear on a user's belt. Other shapes are also possible.

[0021] Yet another embodiment of the present invention is illustrated inFIG. 3. In this embodiment, the ultraviolet bulb 28 protrudes into thecontainer 11 where the liquid is housed. The ultraviolet bulb issurrounded by a lens 22 similar to that of the first two embodiments, ofan appropriate shape.

[0022] The configuration displayed in FIG. 3, as well as similarconfigurations which fall in the scope of the present invention, allowfor greater heat transfer between the ultraviolet bulb 28 and the liquidhoused within the container 11. Ultraviolet bulbs of the type utilizedin this invention may become very hot during operation and burn out. Byproviding a greater surface area of contact between the lens 22 andultraviolet bulb 28, and the liquid, the ultraviolet bulb, will beallowed to cool more easily, and thus avoid burning out. Additionally,the container surface 12 may be formed from a substantially thermalconductive material to indirectly allow the ultraviolet bulb 28 to becooled more efficiently.

[0023] Additionally, though not shown in the figures, a mechanicalfilter of a type well known to those skilled in the art may be attachedto the container surface where the liquid is initially poured into thecontainer 11. In this manner, particulate contaminants may be removedprior to irradiation by ultraviolet light.

[0024] Ultraviolet light can act as a catalyst in the formation of ozonefrom oxygen molecules, readily available in ambient air. Ozone, likeultraviolet light, is an effective water sterilizing agent. Therefore,by allowing air to come into contact with the liquid being purified byultraviolet radiation, the sterilizing action of ozone may also beutilized.

[0025] Having described my invention, however, many modificationsthereto will become apparent to those skilled in the art to which itpertains without deviation from the spirit of the invention as definedby the scope of the appended claims.

I claim:
 1. A portable liquid purification system comprising: acontainer generally capable of housing a liquid; an ultraviolet lightsource; means for said container to securably receive said ultravioletlight source; power supply means for providing electrical power to saidultraviolet light source; an ultraviolet light sensor; and means for anappropriate signal from said ultraviolet light sensor to cause saidultraviolet light source to discontinue emitting ultraviolet radiationand to notify the operator of said portable liquid purification system.2. The portable liquid purification system of claim 1 further comprisinga rigid, liquid impermeable material reflective of ultraviolet lightlining the inside of said container.
 3. The portable liquid purificationsystem of claim 1, said container being formed from a material generallyopaque to ultraviolet light.
 4. The portable liquid purification systemof claim 1 further comprising a light cover situated between saidultraviolet light source and said liquid housed in said container, saidlight cover being formed from a material generally transparent toultraviolet radiation.
 5. The portable liquid purification system ofclaim 1, said power means being covered on at least one side by amaterial opaque to ultraviolet radiation.
 6. The portable liquidpurification system of claim 1 further comprising means for threadablysecuring and removing said ultraviolet light source and said power meansfrom said container.
 7. The portable liquid purification system of claim1 wherein said ultraviolet light source is immersed in liquid duringoperation such that said ultraviolet light source is in thermal contactwith said liquid.